A memory cell including a split-gate-type cell using a metal-oxide-nitride-oxide-semiconductor (MONOS) film is used as a type of a nonvolatile memory, in some cases. At this time, the memory cell includes two MISFETs of a control transistor having a control gate electrode and a memory transistor having a memory gate electrode.
For example, Japanese Patent Application Laid-Open Publication No. 2005-277032 (Patent Document 1) discloses a charge injection method for a nonvolatile semiconductor memory device. More specifically, the document discloses a charge injection method including: an erasing step of erasing data by inducing a second charge, having reverse polarity to that of a first charge, between a semiconductor substrate and either one of source/drain region and injecting the second charge into a charge accumulating layer; and a heating step of rearranging the charge accumulated in the charge accumulating layer by heating the charge accumulating layer by causing a current to flow through a conductive layer in the vicinity of the charge accumulating layer.
Japanese Patent Application Laid-Open Publication No. 2013-93546 (Patent Document 2) discloses a nonvolatile memory including: an insulating film formed between a control gate electrode and a semiconductor substrate; and an insulating film formed between a memory gate electrode and the semiconductor substrate and also between the control gate electrode and the memory gate, the insulating film having a charge accumulating portion inside.